SYDNEY, April 14 (Reuters) - Papua New Guinea’s National Petroleum Company (NPCP) said it is looking to raise billions of dollars to help fund new oil and gas projects, as the South Pacific country battles a sharp slump in forecast revenue from a plunge in prices for the commodities.

NPCP holds a 16.6-percent stake in the PNG LNG project, which operator ExxonMobil Corp wants to expand, and has rights to take up to a 20-percent stake in the Elk-Antelope fields, the country’s largest undeveloped gas resource.

While prospects for new liquefied natural gas developments globally have been hammered by the fallout from a 50-percent drop in oil prices since last June, projects in Papua New Guinea are seen as vital to the country’s economy.

“We are getting a financial adviser on board to work out the structure,” Robert Acevski, chief financial officer at NPCP, told Reuters by telephone on Monday.

“Eventually, we’ll go to the market to raise debt on top of our equity to participate in new projects.”

The projects, which have yet to be finalised, involve multinational firms such as Total SA, Exxon Mobil, Santos and Oil Search. Total operates the Elk-Antelope fields.

Funding an expansion of PNG LNG and any Elk-Antelope development will require NPCP to contribute billions of dollars in the next three years, so it makes sense for it to raise debt well before it needs the money, two industry executives said.

“There was a big increase in revenue that was on the cards only nine months ago, all predicated on the LNG revenue, which is of course drastically reduced. It’s an issue facing the whole country,” said Greg Anderson, executive director of the PNG Chamber of Mines and Petroleum.

An adviser is expected to be appointed within weeks, with the fund raising to kick off later this year or in 2016, Acevski said.

The financing would include “plain” U.S.-denominated debt. The official said it was too early to give an exact amount, but said it would be in billions of dollars.

Papua New Guinea has a debt rating of B-plus from Standard and Poor’s and B1 from Moody’s. Its economy expanded by 8.4 percent last year, making it one of the fastest growing in the world. (Editing by Lincoln Feast and Joseph Radford)